1. Field of the Invention
The present invention relates to a cleaning blade member and, more particularly, to a cleaning blade member for removing toner deposited on a toner image carrier employed in an electrophotographic process such as a photoconductor or a transfer belt, on which a toner image is formed and which transfers the formed image to an image receptor.
2. Background Art
Generally, in an electrophotographic process, electrophotographic apparatus parts such as an electrophotographic photoreceptor and a transfer belt are used cyclically and repeatedly, and toner deposited thereon is removed by means of a cleaning blade. The cleaning blade, which generally comes into contact with a photoreceptor over a long period of time, is required to have excellent wear resistance and a low friction coefficient. In response to the recent trend toward attaining a prolonged service life of units employed in electrophotographic apparatuses, photoreceptors have now a long service life. Thus, the cleaning blade must also have high durability.
In order to enhance the durability of a cleaning blade, the hardness thereof must be increased. However, when the hardness of a conventional single-layer cleaning blade is increased, excessive pressure is applied to a photoreceptor, resulting in exfoliation of a surface layer of the photoreceptor or edge drooping of the cleaning blade, which is problematic. As used herein, the term “edge drooping” refers to drooping of an edge of a cleaning blade, when the opposite edge portion is fixed horizontally on a support such that the surface opposite the photoreceptor contact side is directly placed on the support. Hitherto, there have been proposed some cleaning blades having a multi-layer structure for preventing edge drooping. Japanese Patent No. 2542204 and Japanese Patent Application Laid-Open (kokai) Nos. 2002-214989, 2002-214990, and 2004-184462 disclose those cleaning blades.
The proposed cleaning blades have a plurality of layers formed from different materials. Therefore, one component layer (e.g., a layer which contacts a photoreceptor) compensates for an unsatisfactory property of another component layer, and vice versa. However, wear resistance and edge droop resistance are still unsatisfactory and are to be further improved.